Upgrade validation logic (#275)

This includes upgrades to validation logic for:

- URIs, URI references
- IP addresses and prefixes (v4 and v6)
- Hostname, Port
- Email Address

The validation here adheres to the defined RFC standards for each entity
and passes conformance for all new conformance tests defined in:

- bufbuild/protovalidate#320
- bufbuild/protovalidate#341

---------

Co-authored-by: Timo Stamm <[email protected]>
Co-authored-by: Philip K. Warren <[email protected]>

Author: 3 people

buf.gen.yaml

@@ -2,7 +2,7 @@ version: v2
 managed:
   enabled: true
 plugins:
-    - remote: buf.build/protocolbuffers/python:v29.3
+    - remote: buf.build/protocolbuffers/python:v30.1
       out: gen
-    - remote: buf.build/protocolbuffers/pyi:v29.3
+    - remote: buf.build/protocolbuffers/pyi:v30.1
       out: gen